An RF tag is a miniature transceiver capable of communicating with a remote platform such as an aircraft or a satellite. Existing RF tags are fairly large, power-hungry, and are usually capable of operating with only a single overflying platform. What is therefore needed is a small, rugged device, capable of battery-powered operation for long periods of time, and with programmability to allow operation with many different platforms for which it is to communicate. Also needed is an RF tag for covert use so that troops wearing the RF tag can operate undetected. For commercial use, there is a requirement for vehicle, package and personnel tracking; as well as a need for a convenient light weight search and rescue device which can be worn.